Mullion



FIG. 1 is a front elevational view of a mullion showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and,

FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 2, the broken lines showing adjacent structures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a mullion, as shown and described. 